JP2022136023A - Aliphatic-aromatic polyester composition and method for producing the same - Google Patents

Abstract

To provide an aliphatic-aromatic polyester of high crystallinity which has an aliphatic dicarboxylic acid unit, a furandicarboxylic acid unit, and a butanediol unit.SOLUTION: An aliphatic-aromatic polyester composition contains an aliphatic-aromatic polyester and a nucleating agent. The aliphatic-aromatic polyester has an aliphatic dicarboxylic acid unit, a furandicarboxylic acid unit, and a butanediol unit. The nucleating agent satisfies the condition of the following formula (1): 0°C<Tm1-Tm2≤100°C (where Tm1 is the melting point (°C) of the nucleating agent; and Tm2 is the melting point (°C) of the aliphatic-aromatic polyester).SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to an aliphatic-aromatic polyester composition containing an aliphatic-aromatic polyester having aliphatic dicarboxylic acid units, furandicarboxylic acid units and butanediol units, and a method for producing the same.

Various materials such as paper, plastic, aluminum foil, etc. are used for various applications such as packaging materials for various foods, medicines, miscellaneous liquids, powders, and solids, agricultural materials, and construction materials. . Among them, plastics are excellent in terms of strength, water resistance, moldability, transparency, cost, etc., and are therefore used in various applications such as bags and containers. Currently, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, etc. are used for these applications. However, since these plastic products are difficult to decompose in the natural environment, they may remain in the ground when buried after use, or spoil the landscape when discarded. Moreover, even if it is incinerated, there are problems such as generation of harmful gas and damage to the incinerator.

Biodegradable resins are attracting attention as eco-friendly plastics that solve these problems. Films made of biodegradable resins are decomposed after use, and therefore can prevent global warming and environmental pollution. Therefore, in recent years, biodegradable resin films have been used for garbage bags, shopping bags, and the like.

As biodegradable resins, for example, aliphatic-aromatic polyesters such as polybutylene succinate terephthalate (PBST) and polybutylene succinate furanoate (PBSF) have been proposed. Aliphatic-aromatic polyesters can be produced by polycondensation reaction via esterification reaction and/or transesterification reaction (see Patent Document 1).

However, in general, copolymers including copolyesters tend to be inferior in crystallinity to corresponding homopolymers because they contain copolymer components in the main chain. Especially when polybutylene succinate (PBS) is copolymerized with a furandicarboxylic acid component as an aromatic dicarboxylic acid component, furandicarboxylic acid tends to have a greater effect on the thermophysical properties of the resin than terephthalic acid. It is known that the degree of crystallinity is greatly reduced only by polymerization (Non-Patent Document 1).

JP-A-2008-31457

N. Jacquel et al., Polymer 2015, 59, 234-242. “Bio-based alternatives in the synthesis of aliphatic-aromatic polyesters dedicated to biodegradable film applications.”

When the present inventors produced PBST by the method described in Patent Document 1, it was found that the polyester pellets were blocked due to insufficient crystallization of the obtained polyester. For this reason, even if PBST is used as a film or a molded product such as an inflation-molded bag, there is a concern that problems such as difficulty in cutting due to fusion between films and insufficient opening of the bag may occur. . It has also been found that increasing the crystallization time can result in a lengthy cooling process for the hot polymer, which can be a costly and inefficient process. Furthermore, it was expected that these problems would become more serious, particularly with PBSF in which furandicarboxylic acid is copolymerized with PBS.

The present inventors have made intensive studies to solve the above problems. As a result, in producing an aliphatic aromatic polyester having an aliphatic dicarboxylic acid unit such as PBSF, a furandicarboxylic acid unit, and a butanediol unit by a polycondensation reaction via an esterification reaction and/or a transesterification reaction, the reaction system The inventors have found that the presence of a specific nucleating agent in the nucleating agent can promote crystallization and solve the above problems, and have completed the present invention.
That is, the gist of the present invention resides in the following [1] to [16].

[1] An aliphatic-aromatic polyester composition containing an aliphatic-aromatic polyester and a nucleating agent, wherein the aliphatic-aromatic polyester has an aliphatic dicarboxylic acid unit, a furandicarboxylic acid unit and a butanediol unit, An aliphatic-aromatic polyester composition, wherein the nucleating agent satisfies the following formula (1).
0°C < Tm ¹ - Tm ² ≤ 100°C (1)
(In the above formula (1), Tm ¹ : melting point (° C.) of nucleating agent, Tm ² : melting point (° C.) of aliphatic-aromatic polyester)

[2] The aliphatic-aromatic polyester composition according to [1], wherein the aliphatic dicarboxylic acid unit has a succinic acid unit.

[3] The aliphatic-aromatic polyester composition according to [1] or [2], wherein the molar ratio of succinic acid units to furandicarboxylic acid units is 20:80 to 80:20.

[4] The aliphatic-aromatic polyester composition according to any one of [1] to [3], which contains 0.01 to 100 parts by weight of the nucleating agent with respect to 100 parts by weight of the aliphatic-aromatic polyester. .

[5] The aliphatic-aromatic polyester composition of any one of [1] to [4], further containing a basic compound.

[6] The aliphatic aromatic according to any one of [1] to [5], containing 0.0001 to 0.3 parts by weight of the basic compound with respect to 100 parts by weight of the aliphatic aromatic polyester Polyester composition.

[7] The basic compound contains a metal atom, and the basic compound contains 0.0001 to 0.01 parts by weight of the metal atom relative to 100 parts by weight of the aliphatic aromatic polyester, [5] or The aliphatic-aromatic polyester composition according to [6].

[8] of [5] to [7], wherein the basic compound contains an organic compound, and the organic compound is contained in an amount of 0.0001 to 0.3 parts by weight with respect to 100 parts by weight of the aliphatic aromatic polyester; Aliphatic-aromatic polyester composition according to any one of the above.

[9] The aliphatic-aromatic polyester composition according to any one of [1] to [8], wherein the aliphatic-aromatic polyester has biomass-derived dicarboxylic acid units.

[10] A method for producing an aliphatic-aromatic polyester composition containing an aliphatic-aromatic polyester and a nucleating agent, wherein butanediol, an aliphatic dicarboxylic acid component and a furandicarboxylic acid component are subjected to an esterification reaction and/or An aliphatic-aromatic polyester composition characterized by having a reaction step of conducting a polycondensation reaction via an ester exchange reaction, wherein the nucleating agent satisfying the condition of the following formula (1) is present in the polycondensation reaction system. A method of making things.
0°C < Tm ¹ - Tm ² ≤ 100°C (1)
(In the above formula (1), Tm ¹ : melting point (° C.) of nucleating agent, Tm ² : melting point (° C.) of aliphatic-aromatic polyester)

[11] The method for producing the aliphatic-aromatic polyester composition according to [10], wherein the esterification reaction and/or the transesterification reaction is carried out in the presence of the nucleating agent, A method for producing an aromatic polyester composition.

[12] The method for producing the aliphatic-aromatic polyester composition according to [10] or [11], characterized in that the nucleating agent is supplied to a polycondensation reaction tank in which the polycondensation reaction is performed, A method for producing an aliphatic-aromatic polyester composition.

[13] A method for producing an aliphatic-aromatic polyester composition according to any one of [10] to [12], wherein the extrusion is performed by extruding a molten product from the polycondensation reaction tank in which the polycondensation reaction is performed. and supplying the nucleating agent to the molten product in the extrusion step.

[14] A method for producing an aliphatic-aromatic polyester composition according to any one of [10] to [13], wherein a basic compound is present in the reaction step. A method for making a group polyester composition.

[15] A granular composition comprising the aliphatic-aromatic polyester composition according to any one of [1] to [9].

[16] A molded article obtained by molding the aliphatic-aromatic polyester composition according to any one of [1] to [9].

[17] A film obtained by molding the aliphatic-aromatic polyester composition according to any one of [1] to [9].

[18] A coating material obtained by molding the aliphatic-aromatic polyester composition according to any one of [1] to [9].

[19] A method for producing a granular composition, comprising the steps of extruding the aliphatic-aromatic polyester composition according to any one of [1] to [9] into water and cutting the composition in water.

According to the present invention, an aliphatic-aromatic polyester composition having an aliphatic dicarboxylic acid unit, a furandicarboxylic acid unit and a butanediol unit and having a high degree of crystallinity can be industrially efficiently obtained at low cost. By using this composition, it is possible to obtain resin pellets that are less prone to blocking and films that are less likely to be fused.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram of the cross section explaining the shape of the polyester pellet which concerns on this invention.

BEST MODE FOR CARRYING OUT THE INVENTION Below, embodiments of the present invention will be described in detail. It should be noted that the following description is an example (representative example) of embodiments of the present invention, and the present invention is not limited to these contents as long as the gist thereof is not exceeded.

[Aliphatic-aromatic polyester composition]
The aliphatic-aromatic polyester composition of the present invention (hereinafter sometimes referred to as the "polyester composition of the present invention") is an aliphatic-aromatic polyester (hereinafter referred to as the "aliphatic-aromatic polyester of the present invention" or (Simply referred to as "aliphatic-aromatic polyester" or "polyester") and a nucleating agent. Here, the aliphatic-aromatic polyester has aliphatic dicarboxylic acid units, furandicarboxylic acid units and butanediol units. Also, the nucleating agent satisfies the condition of the following formula (1).
0°C < Tm ¹ - Tm ² ≤ 100°C (1)
(In the above formula (1), Tm ¹ : melting point (° C.) of nucleating agent, Tm ² : melting point (° C.) of aliphatic-aromatic polyester)

Further, the method for producing the aliphatic-aromatic polyester composition of the present invention (hereinafter sometimes simply referred to as "the method for producing the polyester composition of the present invention") contains an aliphatic-aromatic polyester and a nucleating agent. A method for producing an aliphatic-aromatic polyester composition, comprising a step of subjecting butanediol, an aliphatic dicarboxylic acid component and a furandicarboxylic acid component to a polycondensation reaction via an esterification reaction and/or a transesterification reaction, A nucleating agent that satisfies the above formula (1) is present in the polycondensation reaction system.
The polyester composition of the present invention can be obtained by this method for producing the polyester composition of the present invention.

Here, the term "aliphatic dicarboxylic acid component" refers to a compound that serves as a polyester raw material, such as an aliphatic dicarboxylic acid and an aliphatic dicarboxylic acid derivative such as an aliphatic dicarboxylic acid alkyl ester. Further, the term "furandicarboxylic acid component" refers to a compound that serves as a polyester raw material, such as furandicarboxylic acid and furandicarboxylic acid derivatives such as alkyl esters of furandicarboxylic acid. In the present invention, "aromatic" includes "heteroaromatic".
The term "aliphatic dicarboxylic acid unit" refers to a unit derived from the raw material "aliphatic dicarboxylic acid component" of the aliphatic aromatic polyester. Similarly, "furandicarboxylic acid unit" and "butanediol unit" refer to units derived from the raw material "furandicarboxylic acid component" and "butanediol" of the aliphatic aromatic polyester, respectively.

In the method for producing a polyester composition of the present invention, at least butanediol, an aliphatic dicarboxylic acid component and a furandicarboxylic acid component are reacted as main raw materials. The term "butanediol, an aliphatic dicarboxylic acid component and a furandicarboxylic acid component as main raw materials" means that the diol used as a raw material is mainly composed of butanediol, and the dicarboxylic acid component used as a raw material is mainly composed of an aliphatic dicarboxylic acid component and a furandicarboxylic acid component.

Here, "butanediol is the main component" means that the molar ratio of butanediol is the largest in the raw material diol. Among them, butanediol is preferably 50 mol% or more, more preferably 60 mol% or more, still more preferably 70 mol%, based on the total amount of raw material diols, from the viewpoint of the physical properties and biodegradability of the resulting polyester. mol % or more, particularly preferably 90 to 100 mol %.

Further, "mainly containing an aliphatic dicarboxylic acid and a furandicarboxylic acid" means that "the molar ratio of the total amount of the aliphatic dicarboxylic acid component and the furandicarboxylic acid component is the highest among the raw material dicarboxylic acid components." means Among them, from the viewpoint of the physical properties and biodegradability of the obtained polyester, the total amount of the aliphatic dicarboxylic acid component and the furandicarboxylic acid component is preferably 50 mol% or more with respect to the total amount of the raw material dicarboxylic acid component. , more preferably 60 mol % or more, still more preferably 70 mol % or more, and particularly preferably 90 to 100 mol %.

The dicarboxylic acid component used in the present invention is preferably a biomass (plant raw material)-derived compound, and particularly preferably a biomass (plant raw material)-derived furandicarboxylic acid component, from the viewpoint of reducing environmental load. However, on the other hand, PBSF produced using a furandicarboxylic acid component has a slow crystallization rate, and has problems in terms of moldability and productivity. . Therefore, PBSF is preferable as the polyester because it is easy to obtain the effect of promoting crystallization by the combined use of a nucleating agent, and the significance thereof is great.

As methods for producing polyesters, a direct polymerization method using a dicarboxylic acid as a raw material and a transesterification method using an ester derivative of a dicarboxylic acid as a raw material are generally known. Since the transesterification method produces alcohol as a by-product, the direct polymerization method is preferable in terms of safety and economy. However, when the present inventors produced an aliphatic-aromatic polyester by a direct polymerization method using 1,4-butanediol as an aliphatic diol, it was found that tetrahydrofuran was likely to be produced as a by-product. Furthermore, the present inventors have found that the by-production of tetrahydrofuran can be reduced by using a basic compound in the step of conducting polycondensation reaction via esterification reaction and/or transesterification reaction. Therefore, PBSF is preferable as the polyester because it is easy to obtain the combined effect of the basic compound.

<Nucleating agent>
The polyester composition of the present invention contains a nucleating agent that satisfies the condition of formula (1) (hereinafter sometimes simply referred to as "the nucleating agent according to the present invention" or simply "the nucleating agent"). In addition, in the method for producing an aliphatic-aromatic polyester composition of the present invention, a nucleating agent that satisfies the above formula (1) is present in the polycondensation reaction system.
Here, "within the polycondensation reaction system" means the system in which the polycondensation reaction is progressing, and is not limited to the inside of the polycondensation reaction tank in which the polycondensation reaction is performed, and the melt extruded from the polycondensation reaction tank in a molten state. Since the polycondensation reaction proceeds even in the product (extrudate) as long as it is in a molten state, the molten product in the extrusion process is also included in the "polycondensation reaction system" in the present invention. be

In the nucleating agent according to the present invention, the difference (Tm ¹ −Tm ² ) between the melting point (Tm ² (° C.)) of the aliphatic-aromatic polyester to be produced and the melting point (Tm ¹ (° C.)) of the nucleating agent is 0 to 100. °C. By using a nucleating agent that satisfies this condition, crystallization of the resulting aliphatic-aromatic polyester composition is effectively promoted.

The method for evaluating the crystallization-promoting effect is not particularly limited, and can be evaluated by a known method. For example, the effect of promoting crystallization may be evaluated from the crystallization exothermic peak time (cooling crystallization peak time described later) when cooling the molten aliphatic-aromatic polyester composition. In addition, when the aliphatic-aromatic polyester composition is particularly difficult to crystallize and the effect of promoting crystallization cannot be evaluated by the crystallization exothermic peak time, the melting enthalpy ratio ( described later). In addition, the aliphatic-aromatic polyester composition of the present invention is at a temperature equal to or higher than the melting point (Tm ² ) of the aliphatic-aromatic polyester contained therein, and has fluidity suitable for molding, etc. If so, the aliphatic-aromatic polyester composition is considered to be in the molten state, regardless of the molten state of the nucleating agent contained in the composition.

The melting point (Tm ¹ ) of the nucleating agent is usually measured by DSC (differential scanning calorimetry). In addition, it can be measured by a thermal analysis method such as DTA (differential thermal analysis method), or simply by a visual method (JIS K6220). If it is a commercial product, the catalog value can also be adopted.
The melting point (Tm ² ) of the aliphatic-aromatic polyester is also not particularly limited in its measuring method, and can be measured, for example, by the method described in the examples below. Here, the melting point of the aliphatic-aromatic polyester can be measured by measuring the melting point of the polyester produced without using a nucleating agent. A preferred melting point of the aliphatic-aromatic polyester of the present invention will be described later.

In the present invention, the difference (Tm ¹ −Tm ² ) between the melting point (Tm ² (° C.)) of the aliphatic-aromatic polyester and the melting point (Tm ¹ (° C.)) of the nucleating agent is 100° C. or less, preferably It is 50° C. or lower, more preferably 40° C. or lower, still more preferably 30° C. or lower, particularly preferably 20° C. or lower, and most preferably 15° C. or lower. When Tm ¹ -Tm ² is small, a high crystallization promotion effect can be obtained, and the crystallization exothermic peak time can be shortened or the melting enthalpy can be increased. Further, since the cooling time of the high-temperature polymer for crystallization can be shortened, the pellets of the aliphatic-aromatic polyester can be produced efficiently and economically. In addition, an ellipsoidal pellet that is difficult to fuse can be obtained. However, in order for the nucleating agent to act as a crystal nucleus, it is necessary to solidify faster than the aliphatic aromatic polyester, so the lower limit of Tm ¹ -Tm ² is 0 ° C., preferably 1 ° C. Preferably, it is 3°C or higher.

The type of nucleating agent is not particularly limited as long as it satisfies the above conditions. Specifically, for example, hydrocarbon-based nucleating agents such as polyethylene wax and polypropylene wax; aliphatic amide-based nucleating agents; fatty acid amide-based nucleating agents and phenylsulfonic acid metal salt-based nucleating agents can be used. Of these, hydrocarbon-based nucleating agents are preferred, and polyethylene wax is particularly preferred, from the viewpoint of the effect on the color tone and polymerizability of the resulting aliphatic-aromatic polyester composition. Polyethylene waxes are commercially available with various melting points depending on the molecular weight, presence or absence of branching, composition of copolymer components, etc., and it is possible to select and use one that satisfies the above melting point conditions from among these commercially available products. can. The nucleating agent may be used alone or in combination of two or more as long as it satisfies the above melting point conditions.

In the method for producing the aliphatic-aromatic polyester composition of the present invention, the method for allowing the nucleating agent to be present in the polycondensation reaction system is not particularly limited, and the nucleating agent is present when the product in the molten state crystallizes. It's fine if you do. A nucleating agent may be present in the esterification and/or transesterification reaction system. That is, the esterification reaction and/or the transesterification reaction may be carried out in the presence of the nucleating agent by, for example, supplying the nucleating agent to a reactor for the esterification reaction and/or the transesterification reaction prior to the polycondensation reaction. Also, a nucleating agent may be supplied into the polycondensation reaction system. For example, a method of supplying the nucleating agent together with the raw material to the reaction vessel for the esterification reaction and/or the transesterification reaction, a method of supplying the nucleating agent directly to the reaction vessel for the esterification reaction and/or the transesterification reaction separately from the raw material, A method of supplying a nucleating agent to a reactor for condensation reaction (hereinafter sometimes referred to as a "polycondensation reactor"), a molten product in an extruder attached to the polycondensation reactor, etc. and a method of supplying a nucleating agent to. That is, the method of having an extrusion step of extruding a product in a molten state from a polycondensation reaction tank and supplying a nucleating agent to the product in a molten state in this extrusion step is also a method in which the nucleating agent is present in the polycondensation reaction system. included in the method.
Among these methods, the method of supplying the nucleating agent to the reactor for the esterification reaction and/or the transesterification reaction is preferable because the amount of the nucleating agent can be easily controlled. Moreover, the method of supplying the nucleating agent to the polycondensation reaction tank is preferable in terms of easily dispersing the nucleating agent uniformly in the polycondensation reaction system. From the viewpoint of easy control of the crystallization state, it is preferable to supply the nucleating agent when the molten product is crystallized in an extrusion process or the like. These methods may be used alone or in combination of two or more.

The amount of the nucleating agent contained in the aliphatic-aromatic polyester composition of the present invention tends to result in an aliphatic-aromatic polyester with a high degree of crystallinity, that is, in terms of facilitating sufficient crystallization of the polyester during production. A large number is preferable. On the other hand, it is easy to make it highly dispersed, and the resulting composition has excellent moldability and mechanical properties. A small amount is preferable from the viewpoint of easy recovery and reduction of the load of the entire process.

The amount of the nucleating agent is preferably 0.01 parts by weight or more, more preferably 0.02 parts by weight or more, and 0.05 parts by weight or more with respect to 100 parts by weight of the aliphatic-aromatic polyester. is more preferred. On the other hand, the amount of the nucleating agent is preferably 100 parts by weight or less, more preferably 50 parts by weight or less, and 20 parts by weight or less with respect to 100 parts by weight of the aliphatic-aromatic polyester. is more preferable, particularly preferably 10 parts by weight or less, particularly preferably 1 part by weight or less, particularly preferably 0.5 parts by weight or less, and 0.3 parts by weight or less Most preferred.
The amount of the nucleating agent is preferably 0.01 to 100 parts by weight, more preferably 0.01 to 50 parts by weight, and still more preferably 0.01 parts by weight with respect to 100 parts by weight of the aliphatic-aromatic polyester. to 20 parts by weight, particularly preferably 0.01 to 10 parts by weight, particularly preferably 0.01 to 1 part by weight, particularly preferably 0.02 to 0.5 parts by weight, most preferably It is preferably 0.05 to 0.3 parts by weight.

<Diol unit>
The aliphatic-aromatic polyester according to the present invention has butanediol units. The proportion (molar ratio) of butanediol units in the polyester is preferably large from the viewpoint of the melting point (heat resistance) of the polyester, biodegradability, mechanical properties, and the like. Therefore, it is preferable that the proportion of butanediol units is the largest in all diol units. The proportion of butanediol units is preferably 50 mol % or more, more preferably 70 mol % or more, particularly preferably 90 to 100 mol %, based on all aliphatic diol units. The butanediol unit is preferably a 1,4-butanediol unit because it is inexpensive and has excellent reactivity.

The aliphatic-aromatic polyester according to the present invention may have diol units other than butanediol units. Diol units other than butanediol units are preferably aliphatic diol units because they have high reactivity and tend to give a composition having excellent mechanical properties. Examples of aliphatic diol units include raw materials such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, Alkylene diols such as 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, neopentyl glycol; oxyalkylene diols such as diethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol; and cycloalkylenediol such as 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,2-cyclohexanedimethanol, 1,4-cyclohexanedimethanol;

Among these, an alkylenediol unit and a cycloalkylenediol unit are preferable from the viewpoint of physical properties of polyester. Also, the number of carbon atoms is preferably 10 or less, more preferably 6 or less. That is, alkylenediol units or cycloalkylenediol units having 10 or less carbon atoms are preferable, and alkylenediol units or cycloalkylenediol units having 6 or less carbon atoms are more preferable.
In addition, polyester may have diol units other than 2 or more types of butanediol units.
The diol unit is preferably a biomass (plant raw material)-derived unit, and the butanediol unit is more preferably a biomass (plant raw material)-derived unit, from the viewpoint of reducing environmental load.

Diol units are introduced into polyesters by using diols as raw materials. Therefore, as the diol used as a raw material in the method for producing the polyester composition of the present invention, it is preferable to use the diol that becomes the preferred diol unit described above.

<Dicarboxylic acid unit>
The aliphatic-aromatic polyester according to the present invention has aliphatic dicarboxylic acid units and furandicarboxylic acid units. The ratio (molar ratio) of the total amount of aliphatic dicarboxylic acid units and furandicarboxylic acid units in the polyester is preferably large from the viewpoint of the melting point (heat resistance), biodegradability, mechanical properties, and the like of the polyester. Therefore, it is preferable that the ratio of the total amount of these units is the largest in all dicarboxylic acid units. Further, the ratio of the total amount of these units is preferably 50 mol% or more, more preferably 60 mol% or more, particularly preferably 80 to 100 mol%, based on the total dicarboxylic acid units. be.

The dicarboxylic acid unit is preferably a biomass (plant raw material)-derived unit, and more preferably a biomass (plant raw material)-derived unit, from the viewpoint of reducing the environmental load. Moreover, it preferably has a succinic acid unit, an adipic acid unit, a sebacic acid unit, etc. derived from biomass (plant material).

From the viewpoint of heat resistance, biodegradability, mechanical properties, and moldability of polyester, the ratio (molar ratio) of aliphatic dicarboxylic acid units and aromatic dicarboxylic acid units possessed by polyester is aliphatic: aromatic 20: 80 ~80:20, more preferably 30:70 to 70:30, even more preferably 40:60 to 60:40, particularly 50:50 to 60:40 preferable.

The proportion (molar ratio) of the aliphatic dicarboxylic acid units in the polyester is preferably large from the viewpoint of the melting point (heat resistance), biodegradability, mechanical properties, and the like of the polyester. Therefore, it is preferable that the ratio of the aliphatic dicarboxylic acid units is the largest in all the dicarboxylic acid units. The proportion of aliphatic dicarboxylic acid units is preferably 20 mol% or more, more preferably 30 mol% or more, and particularly preferably 35 to 80 mol%, based on the total dicarboxylic acid units. .

The aliphatic dicarboxylic acid unit of the polyester may be either an alicyclic unit or a chain unit, but a chain unit is preferable, and a linear unit is more preferable because the crystallinity tends to be high.
The number of carbon atoms in the main chain constituting the aliphatic dicarboxylic acid unit is preferably large in terms of the flexibility of the resulting composition, and on the other hand, is small in terms of the excellent heat resistance of the resulting composition. preferable. Therefore, the number of carbon atoms in the main chain constituting the aliphatic dicarboxylic acid unit is preferably 18 or less, more preferably 13 or less, still more preferably 10 or less, and particularly preferably 9 or less. Preferably, it is 8 or less, most preferably. On the other hand, the number of carbon atoms in the main chain constituting the aliphatic dicarboxylic acid unit is preferably 2 or more, more preferably 3 or more.

Specific examples of aliphatic dicarboxylic acid units include oxalic acid units, malonic acid units, succinic acid units, succinic anhydride units, glutaric acid units, adipic acid units, pimelic acid units, suberic acid units, azelaic acid units, Aliphatic dicarboxylic acid units such as sebacic acid units, undecadicarboxylic acid units, dodecadicarboxylic acid units, and dimer acid units are included. Among these, the succinic acid unit, the adipic acid unit, and the sebacic acid unit are preferred, and the succinic acid unit is most preferred because the degree of crystallinity tends to be high. Here, the polyester may have two or more of these units.

As described above, the proportion (molar ratio) of aliphatic dicarboxylic acid units in polyester, especially the proportion (molar ratio) of succinic acid, is large from the viewpoint of polyester melting point (heat resistance), biodegradability, mechanical properties, etc. is preferred. Therefore, it is preferable that the ratio of the aliphatic dicarboxylic acid units is the largest in all the dicarboxylic acid units. Further, the proportion of succinic acid units is preferably 20 mol% or more, more preferably 30 mol% or more, and particularly preferably 40 to 100 mol%, based on the total aliphatic dicarboxylic acid units. .

The aliphatic-aromatic polyester according to the present invention has furandicarboxylic acid units. From the viewpoint of the melting point (heat resistance) and mechanical properties of the polyester, it is preferable that the proportion of the furandicarboxylic acid units in the polyester is the largest among all the aromatic dicarboxylic acid units. Therefore, the proportion (molar ratio) of furandicarboxylic acid units is preferably 50 mol% or more, more preferably 70 mol% or more, and particularly preferably 90 to 90 mol% of all aromatic dicarboxylic acid units. 100 mol %.

As described above, a succinic acid unit is preferred as the aliphatic dicarboxylic acid unit. Therefore, the ratio (molar ratio) of succinic acid units and furandicarboxylic acid units in the polyester is preferably 20:80 to 80:20.

The aliphatic-aromatic polyester according to the present invention may have aromatic dicarboxylic acid units other than furandicarboxylic acid units. Dicarboxylic acid units other than furandicarboxylic acid units include, for example, units possessed by polyester when terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, biphenyldicarboxylic acid, or derivatives thereof such as alkyl esters are used as raw materials. mentioned. Of these, terephthalic acid units and isophthalic acid units are preferred, and terephthalic acid units are more preferred, from the viewpoint of physical properties of polyester. These units may be used alone or in combination of two or more. Among these aromatic dicarboxylic acid units, terephthalic acid units and the like are preferably units derived from biomass (plant raw materials).

A dicarboxylic acid unit is introduced into a polyester by using a dicarboxylic acid or the like as a raw material. Aliphatic dicarboxylic acid components used in polyester production are preferably aliphatic dicarboxylic acids and their derivatives such as alkyl esters. The furandicarboxylic acid component used in polyester production is preferably furandicarboxylic acid and its derivatives such as alkyl esters. The aromatic dicarboxylic acid component used in polyester production is preferably an aromatic dicarboxylic acid and derivatives thereof such as alkyl esters. Specifically, aromatic dicarboxylic acids such as hexahydrophthalic acid, hexahydroisophthalic acid and hexahydroterephthalic acid are preferred. and hydrides of Moreover, the dicarboxylic acid component used as a raw material in the method for producing the polyester composition of the present invention preferably uses the dicarboxylic acid that becomes the preferred dicarboxylic acid unit described above in the preferred combination and amount ratio described above.

<Other copolymer units>
The aliphatic-aromatic polyester according to the present invention may have units other than those described above that ordinary polyesters have. That is, in the aliphatic-aromatic polyester according to the present invention, units other than aliphatic diol units, aliphatic dicarboxylic acid units, and aromatic dicarboxylic acid units may be copolymerized. Copolymer units in this case include raw materials such as lactic acid, glycolic acid, hydroxybutyric acid, hydroxycaproic acid, 2-hydroxy-3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, and 2-hydroxyisocaproic acid. , malic acid, maleic acid, citric acid, fumaric acid and other oxycarboxylic acids, esters and lactones of these oxycarboxylic acids, oxycarboxylic acid polymers, etc., or trifunctional or higher such as glycerin, trimethylolpropane, pentaerythritol Polyhydric alcohols, or trifunctional or higher polyvalent carboxylic acids such as propanetricarboxylic acid, pyromellitic acid, trimellitic acid, benzophenonetetracarboxylic acid and their anhydrides, or polyesters when using such anhydrides unit, etc.

Among these, the presence of a small amount of units derived from a tri- or more functional oxycarboxylic acid, a tri- or more functional alcohol, a tri- or more functional carboxylic acid, etc. tends to increase the viscosity of the polyester. Among them, units derived from oxycarboxylic acids such as malic acid, citric acid, and fumaric acid or polyhydric alcohols such as glycerin, trimethylolpropane, and pentaerythritol are preferable, and particularly have units derived from trimethylolpropane. is preferred.

When the polyester has units derived from a trifunctional or higher polyfunctional compound, the ratio is preferably large in terms of easily obtaining the advantages of having units derived from the polyfunctional compound, such as the polyester being likely to have a high viscosity. Also, on the other hand, it is preferable that the content is small in that gel (unmelted matter) is less likely to occur in the polyester. Therefore, the units derived from tri- or more polyfunctional compounds are preferably 0.001 to 5 mol%, more preferably 0.05 to 0.5 mol%, with respect to the total dicarboxylic acid units of the polyester. is.

<Basic compound>
The aliphatic-aromatic polyester composition of the present invention preferably contains a basic compound.
In the method for producing the aliphatic-aromatic polyester composition of the present invention, since butanediol is used as a raw material, tetrahydrofuran may be produced as a by-product in the esterification and/or transesterification reaction steps, as described above. However, the presence of a basic compound here can suppress the by-production of tetrahydrofuran, reduce the amount of tetrahydrofuran in the resulting composition, and reduce the terminal acid value, as will be described later. can be reduced.

The amount of the basic compound contained in the polyester composition of the present invention is preferably large from the viewpoint that tetrahydrofuran is hardly produced as a by-product and the acid value tends to be low. On the other hand, it is preferable that the amount of the by-product is small because the polymerization activity does not easily decrease and the amount of by-products produced by the reaction with the dicarboxylic acid component is small.

Specifically, it is preferably 0.0001 to 0.3 parts by weight, more preferably 0.0001 to 0.01 parts by weight, and 0.001 to 0.01 parts by weight, based on 100 parts by weight of the aliphatic-aromatic polyester. 0001 to 0.005 parts by weight is more preferable.

A basic compound may be an organic compound or an inorganic compound. Moreover, you may use together 2 or more types of basic compounds. When two or more kinds of basic compounds are used in combination, the total amount is preferably within the above range.

Examples of inorganic basic compounds include basic compounds containing metal atoms. Examples thereof include metal salts such as carbonates, hydrogencarbonates, hydroxides, phosphates, borates, acetates, benzoates and citrates. Among these, alkali metal carbonates, hydrogencarbonates, hydroxides, and the like are preferable, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide are more preferable, and hydroxides are most preferable. Sodium.
The amount of the basic compound containing a metal atom contained in the polyester composition of the present invention is 0.0001 to 0.01 part by weight as a metal atom weight with respect to 100 parts by weight of the aliphatic aromatic polyester. It is preferably from 0.0001 to 0.005 parts by weight.

As the basic organic compound, an organic alkali is preferred. Specifically, ammonia, ammonium compounds such as tetraalkylammonium hydroxide; phosphonium compounds such as tetraalkylphosphonium hydroxide; aliphatic amine compounds such as diethylamine and triethylamine; and aromatic amine compounds such as aniline and pyridine are preferred. Alkyl ammonium hydroxides are more preferred, and tetraethylammonium hydroxide is particularly preferred.
The amount of the basic organic compound contained in the polyester composition of the present invention is preferably 0.001-0.3 parts by weight, preferably 0.002-0. 0.25 parts by weight is more preferred.

In the method for producing the aliphatic-aromatic polyester composition of the present invention, the basic compound may be present in the esterification reaction and/or the transesterification reaction. It may be supplied during the esterification reaction and/or the transesterification reaction, or may be supplied to the raw material or the like before the esterification reaction and/or the transesterification reaction. For example, the basic compound may be supplied to the esterification reaction and/or transesterification reaction vessel together with the raw materials such as butanediol, aliphatic dicarboxylic acid component, furandicarboxylic acid component, etc., and may be directly reacted separately from these raw materials. It may be supplied to the tank.

[Method for producing an aliphatic-aromatic polyester composition]
The method for producing an aliphatic-aromatic polyester composition of the present invention has a reaction step of subjecting butanediol, an aliphatic dicarboxylic acid component and a furandicarboxylic acid component to a polycondensation reaction via an esterification reaction and/or a transesterification reaction. . In this polycondensation reaction system, a nucleating agent that satisfies the above formula (1) is present.

Here, as described above, the nucleating agent is supplied to the reaction tank for the esterification reaction and/or the transesterification reaction in that the amount of the nucleating agent can be easily controlled, that is, the esterification reaction and/or the transesterification reaction is performed. It is preferably carried out in the presence of a nucleating agent.
In addition, it is preferable to supply the nucleating agent to the polycondensation reaction tank from the viewpoint of facilitating uniform dispersion of the nucleating agent in the reaction system.
Further, from the viewpoint of easy control of the crystallization state, it is preferable to supply the nucleating agent when the molten product is crystallized, such as in an extrusion process in which the molten product is extruded from the polycondensation reactor.

Each step in the method for producing the aliphatic-aromatic polyester composition of the present invention may be a batch method or a continuous method. However, from the viewpoint of stabilization of the resulting polyester composition and energy efficiency during production, a so-called continuous method in which raw materials are continuously supplied to continuously obtain a polyester composition is preferred. That is, in the method for producing an aliphatic-aromatic polyester of the present invention, butanediol, an aliphatic dicarboxylic acid component and a furandicarboxylic acid component are continuously supplied to a reaction system, and an esterification reaction and / or an ester exchange reaction is performed. It is preferable to have a reaction step of conducting a polycondensation reaction, and it is more preferable to have a step of granulating (pelletizing) while cooling the molten polymer continuously obtained from the polycondensation reactor.

The method for producing the aliphatic-aromatic polyester composition of the present invention will be described below using a continuous method as an example. However, the method for producing the aliphatic-aromatic polyester composition of the present invention is not limited to a continuous method, and conventionally known methods for producing an aliphatic-aromatic polyester can be employed. For example, the direct polymerization method is preferable as the method for producing the aliphatic-aromatic polyester composition of the present invention because alcohol is hardly produced as a by-product and the safety is higher.

Further, in the following description, a method for producing an aliphatic-aromatic polyester composition by an esterification reaction step using butanediol, an aliphatic dicarboxylic acid and a furandicarboxylic acid, and a subsequent polycondensation reaction step will be described in detail. In the method for producing the aliphatic-aromatic polyester composition of the present invention, the ester exchange reaction may be performed instead of the esterification reaction, or the esterification reaction and the ester exchange reaction may be used in combination.
In the following description, the case where the polyester composition is pelletized (hereinafter sometimes referred to as "granular composition") will be described, but the aliphatic-aromatic polyester composition of the present invention is not necessarily pelletized. No need.

In the continuous production method, generally, butanediol (hereinafter sometimes referred to as "diol"), aliphatic dicarboxylic acid and furandicarboxylic acid are subjected to an esterification reaction using a plurality of continuous reaction tanks. Through polycondensation reaction, polyester pellets can be obtained. Here, the esterification reaction step and the subsequent polycondensation reaction step can be carried out in a plurality of continuous reaction tanks or in a single reaction tank. is preferably carried out in a series of reactors.

In the following description, supply of the nucleating agent and the basic compound is omitted, but in the method for producing an aliphatic-aromatic polyester composition of the present invention, as described above, in the polycondensation reaction system, the following The nucleating agent that satisfies the condition of formula (1) is present. Also, preferably, a basic compound is present in the reaction step. As described above, "inside the polycondensation reaction system" in the present invention refers to the inside of the system in which the polycondensation reaction is progressing while the molten state is maintained after the esterification reaction and/or the transesterification reaction. Therefore, the polycondensation reaction system includes the molten product extruded from the polycondensation reaction tank.

<Esterification reaction step>
The reaction temperature in the esterification reaction step is not particularly limited as long as it is a temperature at which the esterification reaction can be carried out, but it is preferably 170° C. or higher, more preferably 180° C., in that the reaction rate can be increased. above, more preferably 200° C. or higher, particularly preferably 210° C. or higher. On the other hand, the reaction temperature is preferably 270° C. or lower, more preferably 260° C. or lower, and still more preferably 250° C. or lower, since the polyester is difficult to color. When the reaction temperature is high, the esterification reaction rate is high, the reaction time is short, and dehydration decomposition of the diol is less likely to occur. In addition, when the reaction temperature is low, decomposition of the raw material components is difficult to occur, foreign matter is less likely to occur due to scattering in the reaction tank, and turbidity (haze) is less likely to occur in the product. The esterification reaction temperature is preferably a constant temperature. The constant temperature stabilizes the esterification rate. The constant temperature is preferably the set temperature ±5°C, more preferably ±2°C.

The reaction atmosphere is preferably an inert gas atmosphere such as nitrogen or argon.

The reaction pressure is preferably 50 kPa or higher, more preferably 60 kPa or higher, even more preferably 70 kPa or higher. On the other hand, the reaction pressure is preferably 130 kPa or less, more preferably 110 kPa or less. That is, the reaction pressure is preferably 50-200 kPa. When the reaction pressure is high, there is little scattering in the reaction vessel, and a product with low haze and little foreign matter can be easily obtained. On the other hand, when the reaction pressure is low, the dehydration decomposition of the diol is difficult to occur, and the polycondensation reaction rate is difficult to decrease.

The reaction time is preferably 1 hour or more, and the upper limit is preferably 10 hours, more preferably 4 hours.

The molar ratio of the diol to the dicarboxylic acid to be esterified is the dicarboxylic acid and ester present in the gas phase and reaction liquid phase of the reaction tank for esterification (hereinafter sometimes referred to as the "esterification reaction tank"). It is the molar ratio of the diol and the esterified diol to the converted dicarboxylic acid, and does not include dicarboxylic acids, diols, and decomposition products thereof that do not contribute to the esterification reaction due to being decomposed in the reaction system. Examples of substances that are decomposed and do not contribute to the esterification reaction include tetrahydrofuran produced by decomposition of 1,4-butanediol, and tetrahydrofuran is not included in this molar ratio. In consideration of this point, the molar ratio of the diol to the dicarboxylic acid subjected to the esterification reaction in the method for producing the aliphatic-aromatic polyester composition of the present invention is usually 1.10 or more, preferably 1.12 or more. , more preferably 1.15 or more, and still more preferably 1.20 or more. On the other hand, the same molar ratio is usually 3.00 or less, preferably 2.50 or less, more preferably 2.30 or less, still more preferably 2.00 or less. When the reaction molar ratio is high, the esterification reaction and the subsequent polycondensation reaction tend to proceed, making it easy to obtain a polyester with a high degree of polymerization. On the other hand, when the reaction molar ratio is low, decomposition of the raw material diol and dicarboxylic acid is less likely to occur. It is a preferred method to appropriately replenish the diol in the esterification reaction so as to keep the reaction molar ratio within the preferred range.

Further, the present inventors have investigated, and found that the amount of tetrahydrofuran produced as a by-product is greater in the esterification reaction than in the transesterification reaction, particularly when the aliphatic-aromatic polyester is PBSF. Therefore, as described above, it is preferable to allow a basic compound to be present. This is because the gas distilled from the reactor for the esterification reaction and the polycondensation reaction contains tetrahydrofuran in addition to diol and water. These gases are usually separated and collected by rectification towers, wet condensers, etc., and some of the high-boiling fractions, which are mainly composed of raw diols, may be reused as raw materials, but tetrahydrofuran is esterified. Since tetrahydrofuran does not contribute to the reaction, a large amount of tetrahydrofuran as a by-product leads to a deterioration in the unit consumption of butanediol. By allowing the basic compound to exist, the by-production of tetrahydrofuran, which causes such problems, can be suppressed.

<Polycondensation reaction step>
In the method for producing the aliphatic-aromatic polyester composition of the present invention, the polycondensation reaction is usually carried out following the esterification reaction step. The polycondensation reaction can be carried out under reduced pressure using a plurality of continuous reactors.
A polyester having a desired viscosity can be obtained by controlling the temperature, time and pressure of the polycondensation reaction.

The reaction pressure in the final polycondensation reactor in the polycondensation reaction is generally 0.01 kPa or higher, preferably 0.03 kPa or higher, and is generally 1.4 kPa or lower, preferably 0.4 kPa or lower. When the pressure in the final polycondensation reaction tank is high, the polycondensation time is short, and accordingly, reduction in molecular weight and coloration due to thermal decomposition of the polyester are less likely to occur, making it easier to obtain a polyester exhibiting practically sufficient properties. On the other hand, it is economically preferable that the reaction pressure is low because expensive equipment is not required.

The reaction temperature in the polycondensation reaction is generally 215° C. or higher, preferably 220° C. or higher, and is generally 270° C. or lower, preferably 260° C. or lower. When the reaction temperature is high, the polycondensation reaction rate is high, a polyester with a high degree of polymerization can be produced in a short time, and stirring is facilitated even with a low lift stirrer, which is economically advantageous. On the other hand, when the reaction temperature is low, thermal decomposition of the polyester is less likely to occur.

The reaction time is generally 1 hour or longer, and is generally 15 hours or shorter, preferably 10 hours or shorter, and more preferably 8 hours or shorter. When the reaction time is long, it is easy to obtain a polyester with a high degree of polymerization, and it is easy to obtain a molded product having excellent mechanical properties. On the other hand, when the reaction time is short, it is difficult for the molecular weight to decrease due to thermal decomposition of the polyester, it is easy to obtain a molded product with excellent mechanical properties, and it is easy to obtain a polyester with a small amount of terminal carboxyl groups and excellent durability.

<Reaction tank>
As the esterification reaction tank, a well-known one can be used, and any type such as a vertical agitation complete mixing tank, a vertical heat convection mixing tank, or a tower-type continuous reaction tank may be used. Moreover, it may be a single tank or a plurality of tanks in which the same or different types of tanks are connected in series. Among them, a reaction tank having a stirring device is preferable, and as the stirring device, in addition to the usual type consisting of a power part, a receiver, a shaft and a stirring blade, a turbine stator type high speed rotary stirrer, a disc mill type stirrer, and a rotor mill type stirrer. A type that rotates at high speed, such as, can also be used. There are no restrictions on the form of stirring, and in addition to the normal stirring method of directly stirring the reaction liquid in the reaction tank from the top, bottom, side, etc. of the reaction tank, a part of the reaction liquid may be piped to the outside of the reaction tank. It is also possible to use a method in which the reaction solution is brought out with a line mixer, etc., and stirred, and the reaction solution is circulated. Known types of stirring blades can be selected, and specific examples include propeller blades, screw blades, turbine blades, fan turbine blades, disk turbine blades, Faudler blades, full zone blades, Maxblend blades, and the like.

The type of the polycondensation reaction tank is not particularly limited, and examples thereof include a vertical stirring polymerization tank, a horizontal stirring polymerization tank, and a thin film evaporation type polymerization tank. The polycondensation reaction tank may be a single tank or a plurality of tanks in which multiple tanks of the same type or different type are connected in series, but in the latter stage of the polycondensation when the viscosity of the reaction liquid increases, the interface renewal property, plug flow property, and self-cleaning are required. It is preferable to select a horizontal stirring polymerization machine having a thin-film evaporation function with excellent performance.

<Catalyst>
Esterification and polycondensation reactions are usually promoted by using a reaction catalyst. When a catalyst is used, if the catalyst is supplied to the gas phase portion of the reaction vessel, the haze of the resulting polyester may increase and the catalyst may become foreign matter, so it is preferable to supply the catalyst into the reaction solution.
In particular, it is preferable to use a catalyst in the polycondensation reaction. The polycondensation reaction catalyst may be supplied at any stage between the esterification reaction step and the polycondensation reaction step. Moreover, the polycondensation reaction catalyst may be supplied in multiple times between the esterification reaction step and the polycondensation reaction step.

As a polycondensation reaction catalyst, a compound containing at least one metal element of groups 1 to 14 of the periodic table is generally used. Here, the periodic table refers to the long period periodic table (Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005). Specific examples of metal elements include scandium, yttrium, samarium, titanium, zirconium, vanadium, chromium, molybdenum, tungsten, tin, antimony, cerium, germanium, zinc, cobalt, manganese, iron, aluminum, magnesium, calcium, Examples include strontium, sodium and potassium. Among them, scandium, yttrium, titanium, zirconium, vanadium, molybdenum, tungsten, zinc, iron and germanium are preferred, and titanium, zirconium, tungsten, iron and germanium are particularly preferred.
In order to reduce the polyester terminal concentration that affects the thermal stability of the polyester, among the above metals, metallic elements of Groups 3 to 6 of the periodic table exhibiting Lewis acidity are preferred. Specifically, they are scandium, titanium, zirconium, vanadium, molybdenum, and tungsten. Titanium and zirconium are particularly preferred from the standpoint of availability, and titanium is particularly preferred from the standpoint of reaction activity.

Also, a titanium compound is preferably used as an esterification reaction catalyst.
Preferred titanium compounds are tetraalkyl titanates and hydrolysates thereof, specifically tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, tetra-t-butyl titanate, tetraphenyl titanate, Tetracyclohexyl titanate, tetrabenzyl titanate and mixed titanates thereof, and hydrolysates thereof.
Also, titanium (oxy) acetylacetonate, titanium tetraacetylacetonate, titanium (diisoproxide) acetylacetonate, titanium bis (ammonium lactate) dihydroxide, titanium bis (ethylacetoacetate) diisopropoxide, titanium (triethanolamine) ) isopropoxide, polyhydroxytitanium stearate, titanium lactate, titanium triethanolamine, butyl titanate dimer, and the like are also preferably used.
Among these are tetra-n-propyl titanate, tetraisopropyl titanate, tetra-n-butyl titanate, titanium (oxy) acetylacetonate, titanium tetraacetylacetonate, titanium bis(ammonium lactate) dihydroxide, polyhydroxytitanium stearate. tetra-n-butyl titanate, titanium (oxy)acetylacetonate, titanium tetraacetylacetonate, polyhydroxytitanium stearate, titanium lactate and butyl titanate dimer are more preferred, and in particular, Tetra-n-butyl titanate, polyhydroxytitanium stearate, titanium (oxy)acetylacetonate, titanium tetraacetylacetonate are preferred.

These catalyst compounds may be used individually by 1 type, or may use 2 or more types together.

These catalyst compounds are usually alcohols such as methanol, ethanol, isopropanol and butanol; diols such as ethylene glycol, butanediol and pentanediol; ethers such as diethyl ether and tetrahydrofuran; nitriles such as acetonitrile; A catalyst solution prepared by using a hydrocarbon compound such as toluene, a solvent such as water and a mixture thereof so that the concentration of the catalyst compound is usually 0.05 to 10% by weight, preferably 0.05 to 5% by weight. is supplied to the esterification reaction step.

<Phosphorus compound>
In the production of the aliphatic-aromatic polyester composition of the present invention, as described above, 1,4-butanediol may be decomposed into tetrahydrofuran, and the basic unit of 1,4-butanediol may decrease. Further, when adipic acid is used as the aliphatic dicarboxylic acid, the resulting polyester may be colored red to pink, and the molded product obtained by molding it may also be tinged with red.
Therefore, as a device for suppressing the by-production of tetrahydrofuran and producing a high-quality polyester with a good color tone, the terminal acid value of the ester oligomer after the esterification reaction is set to 30 to 1000 eq. /ton, and the polycondensation reaction is carried out after contacting the ester oligomer having a controlled terminal acid value with a phosphorus compound.

In this case, the phosphorus compound to be brought into contact with the ester oligomer includes, for example, orthophosphoric acid, polyphosphoric acid, trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, Pentavalent tris (triethylene glycol) phosphate, ethyl diethyl phosphonoacetate, methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, monobutyl phosphate, dibutyl phosphate, dioctyl phosphate, triethylene glycol acid phosphate, etc. Phosphorus compounds; trivalent phosphorus compounds such as phosphorous acid, hypophosphorous acid, diethylphosphite, trisdodecylphosphite, trisnonyldecylphosphite, and triphenylphosphite. Among them, an acidic phosphate ester compound is preferable, and the acidic phosphate ester compound has a phosphoric acid ester structure having at least one hydroxyl group represented by the following general formulas (I) and/or (II): is more preferred.

(Wherein, R, R′ and R″ each represent an alkyl group having 1 to 6 carbon atoms, a cyclohexyl group, an aryl group or a 2-hydroxyethyl group, and R and R′ may be the same or different. is also good.)

Specific examples of the acidic phosphate compound include methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate and octyl acid phosphate. Of these, ethyl acid phosphate and butyl acid phosphate are preferred. A phosphorus compound may be used individually by 1 type, or may use 2 or more types together.

Acidic phosphate ester compounds include the diester represented by the above general formula (I) and the monoester represented by the above general formula (II). , or a mixture of mono- and diesters. The mixing weight ratio of monoester and diester (monoester:diester) is preferably 80 or less:20 or more, more preferably 70 or less:30 or more, particularly preferably 60 or less:40 or more, and On the other hand, it is preferably 20 or more:80 or less, more preferably 30 or more:70 or less, and particularly preferably 40 or more:60 or less.

When a phosphorus compound is used, it is preferred to bring the alkaline earth metal compound into contact with the ester oligomer together with the phosphorus compound. In this case, the alkaline earth metal compound includes various compounds of beryllium, magnesium, calcium, strontium, and barium. From the viewpoint of ease of handling, availability, and effect, compounds of magnesium or calcium are preferable, and among them, catalysts. Magnesium compounds are preferred as they are more effective. Specific examples of the magnesium compound include magnesium acetate, magnesium hydroxide, magnesium carbonate, magnesium oxide, magnesium alkoxide, magnesium hydrogen phosphate, etc. Among these, magnesium acetate is preferred.

The phosphorus compound and the alkaline earth metal compound are 0.01 to 7.6% by weight of the phosphorus compound and the alkaline earth metal compound, using the solvent exemplified as the solvent for dissolving the catalyst used in the preparation of the catalyst solution of the titanium compound described above. It is preferable to supply the ester oligomer supplied to the polycondensation reaction step as a solution prepared so that the metal compound has a concentration of 0.02 to 9.7% by weight.

The catalyst compound used in the esterification reaction step and the amount and ratio of the phosphorus compound and alkaline earth metal compound used in the polycondensation reaction step are not particularly limited. It is preferable to use it so that it becomes 5 to 100 ppm by weight in terms of metal. Further, the phosphorus compound is used so that the phosphorus atom conversion (P/M molar ratio) with respect to the metal amount of the catalyst compound is 0.5 to 2.5, and the alkaline earth metal compound is used so that the alkali metal amount with respect to the metal amount of the catalyst compound is 0.5 to 2.5. It is preferably used so as to be 0.5 to 3.0 in terms of earth metal atoms (alkaline earth metal/M molar ratio). Any compound is preferably used in such an amount that the reaction activity becomes high and thermal decomposition of the polyester hardly occurs. On the other hand, in addition to being economically advantageous, it is easy to obtain a polyester with a low terminal acid value, and less likely to remain in the polyester composition, resulting in a polyester with excellent thermal stability and hydrolysis resistance. Since it is easy to obtain, it is preferable to use a small amount within a range in which the effect can be obtained.

<Raw material supply method>
In the method for producing the aliphatic-aromatic polyester composition of the present invention, the raw materials are usually mixed in advance in a raw material mixing tank, and the mixed raw material is supplied in the form of slurry or liquid to the esterification reactor through a raw material supply line. . When a catalyst is used in the esterification reaction, the diol solution of the catalyst is prepared in the catalyst preparation tank and then supplied to the esterification reaction tank through the catalyst supply line.

<Distilled gas treatment>
The method for producing the aliphatic-aromatic polyester composition of the present invention preferably has a step of treating the gas distilled from the esterification reactor as follows. First, the distillate gas passes through a distillation line and is separated into a high-boiling component and a low-boiling component in a rectifying column. Here, the high-boiling component is mainly composed of a diol such as butanediol, and the low-boiling component is mainly composed of water and a decomposition product of a diol such as butanediol. The high-boiling components separated in the rectification column are withdrawn from the extraction line, and partly circulated from the recycle line to the esterification reactor via a pump, and partly returned to the rectification column from the circulation line. be Also, the surplus is drawn out from the drawing line. On the other hand, the light-boiling components separated in the rectifying column are withdrawn through the gas extraction line, condensed in the condenser, and temporarily stored in the tank through the condensate line. A part of the light-boiling components collected in the tank is returned to the rectification column through the extraction line, pump and circulation line, and the remainder is extracted out of the system through the extraction line. The condenser is connected to an exhaust system via a vent line. The esterification product produced in the esterification reaction tank passes through the discharge pump and the discharge line of the esterification product to the polycondensation reaction tank (when using a plurality of polycondensation reaction tanks, the first polycondensation reaction tank).

<Pelletization>
The method for producing the aliphatic-aromatic polyester composition of the present invention preferably includes a step of granulating (pelletizing) while cooling the molten polymer obtained from the reaction system. The molten polymer can be pelletized using stationary or rotary cutters or pelletizers with or after cooling with water, air, or the like. Pelletization preferably includes a step of extruding the aliphatic-aromatic polyester composition obtained from the reaction system into water and a step of cutting in water.

[Physical properties of the aliphatic-aromatic polyester composition]
As described above, the aliphatic-aromatic polyester composition of the present invention can be obtained by the method for producing the aliphatic-aromatic polyester composition of the present invention. Accordingly, the aliphatic-aromatic polyester composition of the present invention contains a polyester having an aliphatic dicarboxylic acid unit, a furandicarboxylic acid unit and a butanediol unit, and a nucleating agent satisfying the condition of formula (1).
The composition of the aliphatic-aromatic polyester composition of the present invention is also as described above. The amount of polyester contained in the aliphatic-aromatic-aliphatic-aromatic polyester composition of the present invention is 50 to 99.999 weight %. In addition, when the aforementioned basic compound, phosphorus compound or alkaline earth metal is used in the production of the aliphatic-aromatic polyester composition, it is included in the composition.

<Intrinsic viscosity (IV)>
The intrinsic viscosity (IV) of the aliphatic-aromatic polyester composition of the present invention is preferably 1.0 dL/g or more, more preferably 1.2 dL/g or more. On the other hand, the intrinsic viscosity of the aliphatic-aromatic polyester composition of the present invention is preferably 2.5 dL/g or less, more preferably 2.2 dL/g or less, and still more preferably 2.0 dL/g. / g or less. By setting the above-mentioned preferable intrinsic viscosity, the melt viscosity is low, molding is easy, and the mechanical strength of the molded product can be increased. In the present invention, the intrinsic viscosity can be measured by the method described in Examples below.

<Terminal acid value>
It is preferable that the terminal acid value of the polyester contained in the aliphatic-aromatic polyester composition of the present invention is low, because the decrease in viscosity due to hydrolysis is unlikely to occur. Specifically, the terminal acid value is 70 eq. /ton or less, more preferably 50 eq. /ton or less, more preferably 40 eq. /ton or less, particularly preferably 30 eq. / ton or less, particularly preferably 20 eq. /ton or less, most preferably 15 eq. /ton or less. In the present invention, the terminal acid value of the polyester can be measured by the method described in Examples below.

<Melting point ⁽ Tm2)>
The melting point (Tm ² ) of the aliphatic-aromatic polyester composition contained in the aliphatic-aromatic polyester composition of the present invention is not particularly limited, but the aliphatic-aromatic polyester composition of the present invention may A temperature of 100 to 150° C. is preferable because the intrinsic viscosity and the terminal acid value tend to occur. Therefore, the nucleating agent contained in the aliphatic-aromatic polyester composition of the present invention preferably has a melting point (Tm ¹ ) of 100 to 165°C. In the present invention, the melting point of the polyester can be measured by the method described in Examples below.

<Cooling crystal peak time>
As described above, the effect of promoting crystallization by containing the nucleating agent according to the present invention in the aliphatic-aromatic polyester composition of the present invention is obtained by cooling the molten aliphatic-aromatic-aliphatic-aromatic polyester composition. It can be evaluated by the crystallization exothermic peak time, that is, the cooling crystallization peak time.

The temperature-cooling crystallization peak time of the aliphatic-aromatic polyester composition of the present invention can be measured as follows.
10±1 mg of the aliphatic-aromatic polyester composition is placed on an aluminum open pan for DSC measurement, and heated and melted at 200° C. for 10 minutes in a nitrogen atmosphere. In the molten state, the sample pan is set in DSC6220 (manufactured by SII Nano Technology Co., Ltd.), and isothermal measurement at 10° C. is performed. The time when the heat generation due to crystallization reaches the maximum value is recorded, and the same measurement is performed at 20°C, 30°C, and 40°C.
From this DSC measurement, it can be seen that the crystallization is sufficiently accelerated due to the short temperature-falling crystallization peak time.
The temperature-cooling crystallization peak time of the aliphatic-aromatic polyester composition of the present invention is preferably 60 seconds or less, more preferably 50 seconds or less. Although there is no particular lower limit to the cooling crystal peak time, it is usually about 30 seconds.

<Melting enthalpy ratio>
The effect of promoting crystallization by containing the nucleating agent according to the present invention in the aliphatic-aromatic polyester composition of the present invention is also evaluated by the melting enthalpy ratio compared with the composition produced without using the nucleating agent. be able to. It can be seen that crystallization is sufficiently promoted due to the high melting enthalpy ratio. Therefore, the melting enthalpy ratio of the aliphatic-aromatic polyester composition of the present invention is preferably 1.2 or more, more preferably 2 or more, still more preferably 2.5 or more, particularly preferably 3 or more, and most preferably 5 or more. , most preferably 7 or more. The upper limit of the melting enthalpy ratio is not particularly limited. In the present invention, the melting enthalpy can be measured by the method described in Examples below.

[Composition containing the aliphatic-aromatic polyester composition of the present invention]
The aliphatic-aromatic polyester composition of the present invention can be further added to other resins other than the aliphatic-aromatic polyester according to the present invention or to the present invention, depending on the application, required performance, etc., as long as the effects of the present invention are not impaired. It may be mixed with a nucleating agent other than such a nucleating agent, an additive other than a basic compound, and the like. In this case, the amount of the aliphatic-aromatic polyester composition contained in the composition after mixing may be even lower than 50% by weight.
Specifically, as other resins, for example, aliphatic polyesters, aliphatic oxycarboxylic acid-based polyesters, and the like may be blended. Also, biodegradable resins such as polycaprolactone, polyamide, polyvinyl alcohol, cellulose ester; animal and plant powders such as starch, cellulose, paper, wood flour, chitin/chitosan, coconut shell powder, walnut shell powder; carbodiimide compounds; plasticizers and mixtures thereof can be incorporated. In addition, heat stabilizers, lubricants, antiblocking agents, nucleating agents that do not satisfy the formula (1), inorganic fillers, coloring agents, pigments, ultraviolet absorbers, additives such as light stabilizers, modifiers, cross-linking agents, etc. may be included.

The method of producing a composition in which additives and the like are further mixed with the aliphatic-aromatic polyester composition of the present invention is not particularly limited, but a method of melt-mixing blended polyester raw material chips in the same extruder, A method of mixing after melting with separate extruders, and mixing by kneading using an ordinary kneader such as a single screw extruder, a twin screw extruder, a Banbury mixer, a roll mixer, a Brabender plastograph, a kneader blender, etc. and so on. It is also possible to directly supply each raw material chip to a molding machine to prepare a composition and simultaneously obtain a molded product thereof.

[Pellets (granular composition)]
The aliphatic-aromatic polyester composition of the present invention, or a composition obtained by further combining additives and the like, is pelletized using a cutter, pelletizer, etc. in a cooled state (hereinafter, sometimes referred to as "polyester pellets"). can be That is, a granular composition containing the aliphatic-aromatic polyester composition of the present invention can be obtained.

Polyester pellets are usually cylindrical, hemispherical, or spherical or ellipsoidal with a circular or elliptical cross-section. The diameter of the polyester pellets can be adjusted by the outlet diameter from the polycondensation reactor, the discharge speed, the take-up speed, the pelletization speed, and the like. Specifically, it can be adjusted, for example, by the pressure of the polycondensation reaction tank when extracting the polymer, the rotational speed of the blade of the cutter, and the like.

In particular, in the pelletization of a resin having a slow crystallization rate, a cutter equipped with a liquid medium cooling mechanism such as an underwater cutter is preferably used, and an underwater cutter is more preferably used.

The aliphatic-aromatic polyester composition of the present invention or a composition in which an additive is further combined with the composition can be easily formed into an arc-shaped profile that is difficult to fuse. In addition, in order to produce pellets having a shape that is difficult to fuse, it is preferable to use a cutter equipped with a liquid medium cooling mechanism, and more preferably to use an underwater cutter.

Pelletizability can be adjusted by cooling time, cooling temperature, molten resin temperature, and the like. Specifically, for example, the longer the cooling time and the lower the cooling temperature, the more efficiently the pellets immediately after pelletization can be cooled, and the more troubles such as blocking of the pellets can be reduced. On the other hand, excessive cooling tends to decrease the crystallization speed of the resin, impairing productivity and handling properties.

The diameter of the polyester pellets is preferably large in that deterioration due to hydrolysis during storage of the pellets is unlikely to occur, and on the other hand, it is preferable that the diameter is small because it is easy to bite into the extruder and less likely to cause unevenness in the product. Therefore, the lower limit (minimum diameter) is usually 0.1 mm, preferably 0.2 mm, more preferably 0.5 mm, still more preferably 1 mm, while the upper limit (maximum diameter) is usually 20 mm, preferably is 10 mm, more preferably 7 mm, even more preferably 5 mm. The diameter of the polyester pellet indicates the diameter or length of the cross section of the polyester pellet. Moreover, the cross section of the polyester pellet indicates the cross section where the cross-sectional area of the polyester pellet is the maximum.

The shape of the polyester pellets is preferably isotropic because it can be easily bitten into the extruder and tends not to cause product unevenness. The ratio (D1/D2) of the major diameter or longest side length (D1) and the minor diameter or shortest side length (D2) in any cross section of the polyester pellet is preferably 5 or less, more preferably 3 or less, It is more preferably 2 or less, particularly preferably 1.8 or less, even more preferably 1.7 or less, and most preferably 1.6 or less.

The shape of the polyester pellets is preferably a shape having an arc-shaped contour such as a spherical shape or a spheroidal shape. In the case of a shape having an arcuate contour, the contact area when the pellets are in contact with each other becomes smaller than in the case of a cylindrical shape, so that the pellets are less likely to fuse and block. Specifically, for example, as shown in FIG. 1, the length of the line segment in the direction perpendicular to the major axis at each point dividing the major axis or the longest side in any cross section of the polyester pellet into 4 equal parts D2 (midpoint) and When D2' (a point other than the midpoint), the length ratio (D2'/D2) of this line segment is preferably less than 1, preferably 0.95 or less, more preferably 0.93 or less, More preferably 0.90 or less, most preferably 0.88 or less.

[Molded article containing the aliphatic-aromatic polyester composition of the present invention]
The aliphatic-aromatic polyester composition of the present invention can be molded by various molding methods applied to thermoplastic resins. At this time, further resins other than the aliphatic aromatic polyester according to the present invention as described above and nucleating agents other than the nucleating agent according to the present invention may be added depending on the application, required performance, etc., within a range that does not impair the effects of the present invention. Additives other than nucleating agents and basic compounds may be contained.

Examples of the molding method include compression molding (compression molding, laminate molding, stampable molding), injection molding, extrusion molding and co-extrusion molding (film molding by inflation method or T-die method, laminate molding, pipe molding, wire / cable molding , profiled material molding), blow molding (various blow molding), calendar molding, foam molding (melt foam molding, solid phase foam molding), solid molding (uniaxial stretch molding, biaxial stretch molding, roll rolling molding, stretch oriented nonwoven fabric In addition to molding, thermoforming (vacuum molding, air pressure molding), plastic processing), powder molding (rotational molding), various non-woven fabric molding (dry method, adhesion method, entanglement method, spunbond method, etc.), and application or spraying of solutions and then drying to obtain a molded product. The solvent used when the solution process is employed is not particularly limited, but an appropriate one can be selected from the viewpoint of the boiling point of the solvent and the solubility or dispersibility of the composition in the solvent. is preferably used, and halogenated alkyl solvents such as chloroform are particularly preferably used.

Molded articles containing the aliphatic-aromatic polyester composition of the present invention include liquids and powders such as various foods, medicines, miscellaneous goods, packaging materials for packaging solids, agricultural materials, construction materials, etc. It is suitably used in a wide range of applications. Specific uses include injection molded products (e.g. fresh food trays, fast food containers, outdoor leisure products, etc.), extrusion molded products (e.g., films, fishing lines, fishing nets, vegetation nets, water retention sheets, etc.), hollow A molded product (bottle etc.) etc. are mentioned. In addition, other agricultural films, coating materials, fertilizer coating materials, laminated films, boards, stretched sheets, monofilaments, non-woven fabrics, flat yarns, staples, crimped fibers, creased tapes, split yarns, composite fibers, blow bottles, Shopping bags, garbage bags, compost bags, cosmetic containers, detergent containers, bleach containers, ropes, binding materials, sanitary coverstock materials, cooler boxes, cushioning films, multifilament, synthetic paper, surgical thread for medical use, sutures Threads, artificial bones, artificial skins, DDS such as microcapsules, wound dressings, and the like.

In addition, information electronic materials such as toner binders and thermal transfer ink binders, packaging materials such as packaging films, fruit and vegetable bags, shopping bags, compost bags, bags, trays, bottles, cushioning foams, fish boxes, etc. and agricultural materials such as mulching films, tunnel films, house films, shades, weed control sheets, ridge sheets, germination sheets, vegetation mats, nursery beds, flower pots and the like.

The molded article of the present invention is excellent in impact resistance, mechanical properties such as tear strength and tensile elongation at break, and biodegradability. is particularly preferred.
The thickness of the film of the present invention formed by molding the aliphatic-aromatic polyester composition of the present invention or a composition obtained by further combining additives and the like is appropriately designed according to the application, and is not particularly limited. is usually about 5 μm to 1 mm.

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Methods for measuring physical properties and evaluation items are as follows.

<Intrinsic viscosity (IV) (dL/g)>
Using an Ubbelohde viscometer, it was determined in the following manner. That is, using a mixed solvent of phenol / tetrachloroethane (weight ratio 1/1), at 30 ° C., measuring the number of seconds of dropping the polyester composition solution with a concentration of 0.5 g / dL and the solvent only, the following formula ( 2).
IV=((1+4K _H η _SP ) ^0.5 −1)/(2K _H C) (2)

However, η _SP = η/η ₀ −1, where η is the number of seconds the sample solution falls, η ₀ is the number of seconds the solvent falls, C is the concentration of the sample solution (g/dL), and K _H is Huggins constant. is. _KH adopted 0.33.

<Terminal acid value (eq./ton)>
The terminal acid value of the ester oligomer was obtained in the following manner.
0.3 g of pasty ester oligomer was placed in a 100 mL beaker, 40 mL of benzyl alcohol was added, and the mixture was heated on a hot plate at 180° C. while blowing dry nitrogen gas. After 20 minutes had passed while confirming that the solution was dissolved, the temperature was lowered to 60°C by cooling with water. 10 mL of benzyl alcohol was used to wash back the drops attached to the beaker wall, and 1 to 2 drops of phenol red indicator was added to this solution (the total amount of the solution in the beaker including the washed-off liquid), and the mixture was stirred while blowing dry nitrogen gas. , with a 0.1 mol/L methanol solution of potassium hydroxide, and the titration was terminated when the color changed from yellow to red. As a blank, the same operation was performed using only benzyl alcohol, and the terminal acid value (the amount of terminal carboxy groups) was calculated according to the following formula (3).

The terminal acid value (eq./ton) of polyester was obtained in the following manner.
The pelletized polyester or polyester composition was dried in a vacuum dryer at 60°C for 8 hours and cooled to room temperature (25°C) in a desiccator. 0.5 g of this sample was precisely weighed and collected in a test tube, 25 mL of benzyl alcohol was added, and the sample was dissolved at 195° C. for 3 minutes while blowing dry nitrogen gas. Then, after stirring for 40 seconds while cooling using an ice bath, 2 mL of ethanol was gradually added. Add 1 to 2 drops of phenol red indicator to this solution, titrate with a 0.1 mol/L sodium hydroxide benzyl alcohol solution while stirring while blowing dry nitrogen gas, and finish when the color changes from yellow to red. did. As a blank, the same operation was performed without adding the polyester sample, and the terminal acid value (the amount of terminal carboxy groups) was calculated by the following formula (3).

Calculation of the terminal acid value was obtained from the following formula.
Terminal acid value (eq./ton) = (ab) x 0.1 x f/w (3)
Here, a is the amount (μL) of 0.1 mol/L sodium hydroxide benzyl alcohol solution required for titration, and b is 0.1 mol/L sodium hydroxide benzyl alcohol required for blank titration. The amount of alcohol solution (μL), w is the amount of ester oligomer or polyester sample (g), f is the titer of 0.1 mol/L sodium hydroxide solution in benzyl alcohol.
Here, the titer (f) of a 0.1 mol/L sodium hydroxide solution in benzyl alcohol was obtained by the following method. 5 cm ³ of methanol was collected in a test tube, and 1 to 2 drops of phenol red was added as an indicator of the ethanol solution. Titrate with 0.4 cm ³ of 1 mol/L benzyl alcohol solution of sodium hydroxide to the color change point, then add 0.2 cm ³ of 0.1 mol/L hydrochloric acid aqueous solution with known potency as a standard solution, Titration was carried out with a 0.1 mol/L benzyl alcohol solution of sodium hydroxide until the color change point (the above operation was performed while blowing dry nitrogen gas). Then, the titer (f) was calculated by the following formula (4).
Potency (f) = titer of 0.1 mol/L hydrochloric acid aqueous solution x collected amount (μL) of 0.1 mol/L hydrochloric acid aqueous solution/titration amount of 0.1 mol/L sodium hydroxide benzyl alcohol solution ( μL) (4)

<Melting point of polyester (°C)>
Using DSC7020 (manufactured by Hitachi High-Tech Science Co., Ltd.), polyester produced without using a nucleating agent was heated from room temperature (25°C) to 250°C at a rate of 20°C/min, and the endothermic peak temperature was measured. was taken as the melting point of the polyester.

<Melting enthalpy ratio>
Measurement was performed using DSC7020 (manufactured by Hitachi High-Tech Science), after heating from room temperature to 200 ° C. at a rate of 10 ° C./min, cooling from 200 ° C. to -50 ° C. at a rate of 10 ° C./min. The temperature was raised from -50°C to 200°C at a rate of 10°C/min.
The aliphatic-aromatic polyester composition of the present invention and the polyester obtained by removing the nucleating agent from this composition were subjected to DSC measurement by the above method. Here, the area of the endothermic peak corresponding to the melting of the sample resin in the second heating process is defined as the melting enthalpy (ΔHm and ΔHm ₀ , respectively). At this time, the value obtained by dividing ΔHm by ΔHm ₀ (ΔHm/ΔHm ₀ ) was defined as the melting enthalpy ratio and used for evaluation.

<Pelletization>
After the pellets obtained by cutting are allowed to cool to room temperature (25° C.), ◯ means that the pellets are not blocked at all, or if they are blocked, they can be easily disassembled by hand. Δ indicates that the pellet could be unraveled by hand, and x indicates that a plurality of pellets are fused together and cannot be easily separated by hand.

[Example 1]
24.2 parts by weight of succinic acid, 48.0 parts by weight of 2,5-furandicarboxylic acid and 92 parts by weight of 1,4-butanediol were added to a reaction vessel equipped with a stirring device, a nitrogen inlet, a heating device, a thermometer and a pressure reducing port. .4 parts by weight, 0.138 parts by weight of trimethylolpropane and 1.00 parts by weight of polyethylene wax (“ACumist B6” manufactured by Honeywell, melting point: 124° C.) are charged, and further tetra-n-butyl titanate is obtained per polyester It was added so as to be 30 ppm by weight as titanium atoms. Here, the succinic acid/furandicarboxylic acid molar ratio is 40/60. Moreover, 1.0 part by weight of polyethylene wax is used per 100 parts by weight of polyester obtained.

Nitrogen gas was introduced into the vessel while stirring the contents of the reaction vessel, and the inside of the system was made into a nitrogen atmosphere by decompression replacement. Next, while stirring the inside of the system, the temperature was raised from 170° C. to 190° C. over 1 hour, and the reaction was carried out at this temperature for 1 hour. After that, an amount of 70 ppm by weight of titanium atoms per polyester to obtain tetra-n-butyl titanate was further added, and the temperature was raised to 240° C. over 1.5 hours, and at the same time, 0.07 over 1.5 hours. The pressure was reduced to ×10 ³ Pa or less, and the polycondensation was continued while maintaining the heating and reduced pressure. After 1 hour, the polymerization was terminated to obtain an aliphatic-aromatic polyester composition.

[Comparative Example 1]
An aliphatic-aromatic polyester was produced in the same manner as in Example 1, except that polyethylene wax was not used. Here, the time from the start of depressurization to the end of the reaction (polymerization time) was 138 minutes, the polymerization rate was 0.0097 dL/g/min, and the intrinsic viscosity was 1.138 dL/g. The melting point of the obtained polyester was 109°C.
The distillate in the esterification reaction and the polycondensation reaction was recovered, the tetrahydrofuran concentration was measured by gas chromatography, and the amount of tetrahydrofuran by-product (THF by-product) was calculated. part by weight.

[Example 2]
24.2 parts by weight of succinic acid, 48.0 parts by weight of 2,5-furandicarboxylic acid and 92 parts by weight of 1,4-butanediol were added to a reaction vessel equipped with a stirring device, a nitrogen inlet, a heating device, a thermometer and a pressure reducing port. .4 parts by weight and 0.138 parts by weight of trimethylolpropane were charged, and further added so as to give 30 ppm by weight of titanium atoms per polyester from which tetra-n-butyl titanate was obtained. While stirring the contents of the reaction vessel, nitrogen gas was introduced into the vessel, and the inside of the system was made into a nitrogen atmosphere by decompression replacement. Next, while stirring the inside of the system, the temperature was raised from 170° C. to 190° C. over 1 hour, and the reaction was carried out at this temperature for 1 hour. After that, an amount of 70 ppm by weight of titanium atoms per polyester to obtain tetra-n-butyl titanate was further added, and the temperature was raised to 240° C. over 1.5 hours, and at the same time, 0.07 over 1.5 hours. The pressure was reduced to ×10 ³ Pa or less, and the polycondensation reaction was further carried out for 31 minutes while maintaining the heating and reduced pressure. Next, 1.00 parts by weight of polyethylene wax (“Luwax AH3” manufactured by BASF, melting point: 113° C.) is added to 100 parts by weight of the molten resin and kneaded to obtain an aliphatic-aromatic polyester composition. rice field.

[Examples 3-5 and Comparative Examples 2-3]
In Example 2, polyethylene wax ("Luwax AH3" manufactured by BASF) was replaced with polyethylene wax ("ACumist A6" manufactured by Honeywell, melting point: 132 ° C.), fatty acid amide ("Slipax H" manufactured by Mitsubishi Chemical, compound name : ethylenebis-12-hydroxystearic acid amide, melting point: 145°C), phenylphosphonic acid metal salt (manufactured by Nissan Chemical Industries, Ltd. "Ecopromot", compound name: zinc phenylphosphonate, melting point: 163-166°C), talc ( Nippon Talc Co., Ltd. “Nano Ace D-600”, melting point: 900 ° C. or higher (decomposition)), talc (Nippon Talc Co., Ltd. “MS-KY”, melting point: 900 ° C. or higher (decomposition)). Each aliphatic-aromatic polyester composition was produced in the same manner, including the amount (weight ratio) of the nucleating agent relative to the polyester.

[Example 6]
The molten aliphatic-aromatic polyester composition obtained in Example 1 was subjected to a twin-screw extruder (manufactured by Parker Corporation, HK- 25D (41D), cylinder temperature: 220 ° C.), melt-kneaded, and cut to form spheroidal pellets (long diameter: about 5 mm, short diameter: about 3 mm) made of the aliphatic-aromatic polyester composition. manufactured. The aforementioned D2'/D2 ratio in this pellet was 0.87. The obtained pellet was cooled with cooling water at 20° C. for several seconds and dehydrated by centrifugation.

[Example 7]
An aliphatic-aromatic polyester composition was produced in the same manner as in Example 1, except that the amount of polyethylene wax charged was reduced to 1/10 the amount, and this aliphatic-aromatic polyester composition was used in Examples In the same manner as in Example 6, pellets of an aliphatic-aromatic polyester composition having a spheroidal shape (major axis: 5 mm, minor axis: 3 mm) were produced. The aforementioned D2'/D2 ratio in this pellet was 0.87. Here, 0.1 part by weight of polyethylene wax was used per 100 parts by weight of polyester obtained.

In both Examples 6 and 7, no significant fusion was observed in the pellets after cutting and before cooling and dehydration. In particular, when the cooling water temperature of the underwater cutter was lowered, the tendency of the fusion to be reduced was recognized.

[Reference example 1]
A molten aliphatic-aromatic polyester composition was produced in the same manner as in Example 1, and the obtained composition was extracted in a strand, removed from the heat in a water bath, and then cut with a rotary blade pelletizer to obtain an aliphatic Cylindrical pellets (cross-sectional diameter: 2 mm, length: 5 mm) were produced from an aromatic polyester composition. The aforementioned D2'/D2 ratio in this pellet was 0.87-1.

[Example 8]
Aliphatic-aromatic polyester composition was prepared in the same manner as in Example 1, except that tetraethylammonium hydroxide (Et ₄ NOH, manufactured by Tokyo Chemical Industry Co., Ltd.) was added to obtain 300 ppm by weight per polyester when the raw materials were charged. manufactured things. Here, the time (polymerization time) from the start of depressurization to the end of the reaction was 142 minutes, the polymerization rate was 0.0096 dL/g/min, and the intrinsic viscosity was 1.378 dL/g.
The distillate in the esterification reaction and the polycondensation reaction was collected, the tetrahydrofuran concentration was measured by gas chromatography, and the amount of tetrahydrofuran by-product (THF by-product) was calculated. part by weight.

[Example 9]
Aliphatic-aromatic polyester was prepared in the same manner as in Example 1, except that sodium hydroxide (NaOH, manufactured by Tokyo Kasei Kogyo Co., Ltd.) was added at the same time as the raw materials were added so that the sodium atom was 30 ppm by weight per polyester. A composition was produced. Here, the time from the start of depressurization to the end of the reaction (polymerization time) was 160 minutes, the polymerization rate was 0.0079 dL/g/min, and the intrinsic viscosity was 1.263 dL/g.
The distillate in the esterification reaction and the polycondensation reaction was recovered, the tetrahydrofuran concentration was measured by gas chromatography, and the amount of tetrahydrofuran by-product (the amount of THF by-product) was calculated. part by weight.

[Comparative Example 4]
In Comparative Example 1, the charging ratio of raw materials, etc. was 22.3 parts by weight of succinic acid, 52.2 parts by weight of dimethyl 2,5-furandicarboxylate, 68.1 parts by weight of 1,4-butanediol, and 0 part by weight of trimethylolpropane. An aliphatic-aromatic polyester containing no nucleating agent was produced in the same manner, except that the amount was 0.138 parts by weight. Here, the succinic acid/dimethyl furandicarboxylate molar ratio is 40/60. The time from the start of decompression to the end of the reaction (polymerization time) was 126 minutes, the polymerization rate was 0.0103 dL/g/min, and the intrinsic viscosity was 1.299 dL/g.
The distillate in the esterification reaction and the polycondensation reaction was recovered, the tetrahydrofuran concentration was measured by gas chromatography, and the amount of tetrahydrofuran by-product (the amount of THF by-product) was calculated. part by weight.

The physical properties of the aliphatic-aromatic polyester compositions obtained in Examples 1-8, Comparative Examples 2-3 and Reference Example 1, and the aliphatic-aromatic polyesters obtained in Comparative Examples 1 and 4 were measured. The results are shown in Table 1 together with the manufacturing conditions. In Table 1, the difference (Tm ¹ -Tm ² ) between the melting point (Tm ¹ ) of the nucleating agent and the melting point (Tm ² ) of the polyester is indicated as "ΔTm".

From Table 1, the aliphatic-aromatic polyester compositions of Examples 1 to 5 containing a nucleating agent that satisfies the formula (1) according to the present invention are the aliphatic-aromatic polyester of Comparative Example 1 that does not contain a nucleating agent and the formula Compared to Comparative Examples 2 and 3 using nucleating agents that do not satisfy (1), the value of ΔHm/ΔHm ₀ is large, indicating that crystallization is promoted by the nucleating agent that satisfies the formula (1) according to the present invention. backed up.
Further, from Examples 6 and 7, the aliphatic-aromatic polyester composition containing the nucleating agent satisfying the formula (1) according to the present invention can be made into spheroidal pellets that are difficult to fuse, and that the spheroidal It was confirmed that the underwater cutter is effective for producing shaped pellets.
A large amount of THF was by-produced in Comparative Example 1 using furandicarboxylic acid as compared with Comparative Example 4 using dimethyl furandicarboxylate as a raw material. However, from a comparison of the amount of by-product THF in Examples 8 and 9 using a basic compound and Comparative Example 1 not using a basic compound, even when furandicarboxylic acid was used as a raw material, the basic compound It was confirmed that the by-production of THF can be reduced by using.

Claims (19)

An aliphatic-aromatic polyester composition containing an aliphatic-aromatic polyester and a nucleating agent, wherein the aliphatic-aromatic polyester has an aliphatic dicarboxylic acid unit, a furandicarboxylic acid unit and a butanediol unit, and the nucleating agent satisfies the conditions of the following formula (1), an aliphatic-aromatic polyester composition.
0°C < Tm ¹ - Tm ² ≤ 100°C (1)
(In the above formula (1), Tm ¹ : melting point (° C.) of nucleating agent, Tm ² : melting point (° C.) of aliphatic-aromatic polyester) 2. The aliphatic-aromatic polyester composition of claim 1, wherein said aliphatic dicarboxylic acid units have succinic acid units. 3. The aliphatic-aromatic polyester composition according to claim 1, wherein the molar ratio of succinic acid units: furandicarboxylic acid units is from 20:80 to 80:20. 4. The aliphatic-aromatic polyester composition according to any one of claims 1 to 3, containing 0.01 to 100 parts by weight of the nucleating agent per 100 parts by weight of the aliphatic-aromatic polyester. 5. The aliphatic-aromatic polyester composition according to any one of claims 1 to 4, further comprising a basic compound. The aliphatic-aromatic polyester composition according to any one of claims 1 to 5, wherein the basic compound contains 0.0001 to 0.3 parts by weight with respect to 100 parts by weight of the aliphatic-aromatic polyester. . 7. The basic compound according to claim 5 or 6, wherein the basic compound contains a metal atom, and the basic compound contains 0.0001 to 0.01 parts by weight of the metal atom relative to 100 parts by weight of the aliphatic-aromatic polyester. of an aliphatic-aromatic polyester composition. Any one of claims 5 to 7, wherein the basic compound contains an organic compound and contains 0.0001 to 0.3 parts by weight of the organic compound relative to 100 parts by weight of the aliphatic aromatic polyester. The aliphatic-aromatic polyester composition described. The aliphatic-aromatic polyester composition according to any one of claims 1 to 8, wherein the aliphatic-aromatic polyester has biomass-derived dicarboxylic acid units. A method for producing an aliphatic-aromatic polyester composition containing an aliphatic-aromatic polyester and a nucleating agent, wherein butanediol, an aliphatic dicarboxylic acid component and a furandicarboxylic acid component are subjected to an esterification reaction and/or a transesterification reaction. Production of an aliphatic-aromatic polyester composition, characterized in that the nucleating agent that satisfies the following formula (1) is present in the polycondensation reaction system: Method.
0°C < Tm ¹ - Tm ² ≤ 100°C (1)
(In the above formula (1), Tm ¹ : melting point (° C.) of nucleating agent, Tm ² : melting point (° C.) of aliphatic-aromatic polyester) 11. The method for producing an aliphatic-aromatic polyester composition according to claim 10, wherein the esterification reaction and/or the transesterification reaction is carried out in the presence of the nucleating agent. A method for producing a polyester composition. 12. The method for producing the aliphatic-aromatic polyester composition according to claim 10 or 11, wherein the nucleating agent is supplied to a polycondensation reaction tank in which the polycondensation reaction is performed. A method of making the composition. The method for producing the aliphatic-aromatic polyester composition according to any one of claims 10 to 12, comprising an extrusion step of extruding a product in a molten state from a polycondensation reaction tank for performing the polycondensation reaction. and supplying the nucleating agent to the molten product in the extrusion step. A method for producing the aliphatic-aromatic polyester composition according to any one of claims 10 to 13, wherein a basic compound is present in the reaction step, the aliphatic-aromatic polyester composition A method of making things. A granular composition comprising the aliphatic-aromatic polyester composition according to any one of claims 1 to 9. A molded article obtained by molding the aliphatic-aromatic polyester composition according to any one of claims 1 to 9. A film obtained by molding the aliphatic-aromatic polyester composition according to any one of claims 1 to 9. A coating material obtained by molding the aliphatic-aromatic polyester composition according to any one of claims 1 to 9. A method for producing a granular composition, comprising a step of extruding the aliphatic-aromatic polyester composition according to any one of claims 1 to 9 into water and a step of cutting in water.

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